Practise

Question bank

Original exam-style questions, mapped to your syllabus. Answers are checked for mathematical equivalence and every attempt updates your mastery.

TopicSkillDifficulty

12 questions

SA-9709-P6-SE-0071 markL1 FoundationCalculatorSampling

Why is a random sample used?

Salam Academy Original Practice · Proposed mark scheme

SA-9709-P6-SE-0101 markL1 FoundationCalculatorUnbiased estimates

An unbiased estimate of population variance from a sample of size

n

divides by

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SA-9709-P6-SE1-0013 marksL1 FoundationCalculatorUnbiased estimates

A sample of

8

values has

\Sigma x=96

and

\Sigma x^2=1200

. Find unbiased estimates of the population mean and variance (variance to 3 s.f.).

Salam Academy Original Practice · Proposed mark scheme

SA-9709-P6-SE1-0021 markL1 FoundationCalculatorUnbiased estimates

A sample of

5

values has variance

4

(calculated with divisor

n

). Find an unbiased estimate of the population variance.

Salam Academy Original Practice · Proposed mark scheme

SA-9709-P6-SE1-0031 markL1 FoundationCalculatorSampling

Which is a way of taking a random sample of

20

students from a school of

800

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SA-9709-P6-SE1-0041 markL1 FoundationCalculatorSampling

To estimate how often students exercise, a researcher questions the first

20

students at the gym. The main problem is that

Salam Academy Original Practice · Proposed mark scheme

SA-9709-P6-SE1-0061 markL1 FoundationCalculatorSampling

In statistics, the "population" is

Salam Academy Original Practice · Proposed mark scheme

SA-9709-P6-SE-G013 marksL1 FoundationCalculatorUnbiased estimates

A sample of

10

values gives

\Sigma x=52

and

\Sigma x^2=290

. Find unbiased estimates of the population mean and variance (variance to 3 s.f.).

Salam Academy Original Practice · Proposed mark scheme

SA-9709-P6-SE-Q031 markL1 FoundationCalculatorSampling

A sample is used rather than a census because

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SA-9709-P6-SE-0013 marksL2 StandardCalculatorUnbiased estimates

A sample of

50

values gives

\Sigma(x-20)=35

and

\Sigma(x-20)^2=1250

. Find unbiased estimates of the population mean and variance (variance to 3 s.f.).

Salam Academy Original Practice · Proposed mark scheme

SA-9709-P6-SE1-0053 marksL2 StandardCalculatorUnbiased estimates

A random sample of

5

values is

3,\ 5,\ 6,\ 8,\ 8

. Find unbiased estimates of the population mean and variance.

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SA-9709-P6-SE1-0074 marksL3 ExamCalculatorUnbiased estimates

For a sample of

20

values,

\Sigma(x-10)=30

and

\Sigma(x-10)^2=225

. Find unbiased estimates of the population mean and variance (variance to 3 s.f.).

Salam Academy Original Practice · Proposed mark scheme